Hair relaxers are used for permanent straightening of curly and/or kinky hair. Such products may be used by women of various ancestries, such as African, North or South American, Asian, Middle Eastern or European ancestry, who may have curly or kinky hair that they may wish to straighten or relax. The relaxer is typically an alkali (that is, a base having a pH that is higher than neutral) that breaks the natural disulfide bonds within the hair. The user mechanically straightens the hair. Then the disulfide bonds are essentially “reformed” in the straightened hair in conjunction with neutralization of the active ingredient in the relaxer, which is often a strong alkali.
The alkali relaxers for which the neutralizing compositions and methods of the present invention are applicable include those comprising a strong alkali. The neutralizing compositions and methods contained within may also work on a weak alkali, such as monoethanolamine, triethanolamine, and ammonium hydroxide, which may be used to lessen the degree of curl by weakening the disulfide bonds. In addition to breaking the disulfide bonds, these types of relaxers also tend to have the undesirable effect of stripping the fatty acids from the hair, leading to weak, dry and brittle hair.
There are two common types of alkali hair relaxers. The first type is known as a “lye relaxer,” and includes formulations that contain sodium hydroxide, lithium hydroxide, or potassium hydroxide (the alkali earth metal hydroxides). These lye relaxers are usually supplied in cream form and are applied directly to the hair. Lye relaxers were developed in the early part of the 20th century. Because of the inherent dangers to hair and skin of sodium hydroxide and other alkali metal hydroxides, lye relaxers are usually relegated to the professional sector of the hair care market.
The second type of alkali relaxer is known as a “no-lye relaxer.” No-lye relaxers were developed in the 1970s and make up the bulk of the non-professional or home use market sector. A no-lye relaxer system comprises a precursor cream that contains an alkali earth metal hydroxide, such as calcium hydroxide, which is mixed with a liquid “activator” that contains a strong nitrogenous base, such as guanidine carbonate. The activator liquid and the precursor cream are mixed just prior to use. There is a chemical reaction between these components, such as between the calcium hydroxide in the precursor cream and the guanidine carbonate in the liquid. This reaction produces the hair relaxing agent in activated form, in this case, guanidine hydroxide, which becomes the active alkali in treating the hair.
Thus, a difference between a “lye relaxer” and a “no-lye relaxer” is that a lye relaxer does not require a separate activator to produce the active relaxing agent (e.g., the sodium hydroxide or lithium hydroxide). Another difference is in the chemical reaction products that result when the lye relaxers or no-lye relaxers are subsequently neutralized.
All alkali relaxers are meant to be applied to the hair for a specific period of time, after which they are to be rinsed off, and thereafter neutralized, to stop the action of the residual relaxer. Typically, the neutralizing is done by way of an acidic shampoo, and the hair is then conditioned with a rinse-out and/or leave-in conditioner. Generally, such acidic shampoos contain water soluble acids such as citric acid, ascorbic acid and the like, to further their goal of lowering the pH of the hair after relaxer treatment.
As a next step, the hair is often further shampooed or conditioned. Commercial products currently exist that may include oils and lipids as conditioning agents or as claim ingredients solely for marketing purposes. For example, a shampoo marketed for neutralizing purposes and known as “Elasta QP Soy Oil” available from Strength of Nature Co. (Savannah, Ga., USA) contains soy oil. In another example, a product known as “Soft & Beautiful®” is commercially available from Alberto-Culver Co. (UK) Ltd. Additionally, there is historical evidence to suggest that women have applied oils and products such as eggs to their hair for conditioning purposes.
However, the products historically and currently used are generally not adequate for neutralizing purposes for several reasons: first, where any fatty acids may be included in known hair care products, the amounts of fatty acids present are generally miniscule and generally not sufficient to neutralize the user's hair. Further, mixing fatty acid with alkaline relaxers in commercial formulations generally leads to neutralized relaxers, not neutralized hair. In fact, adding anything containing a fatty acid to a relaxer in accordance with known methods or compositions is not expected to provide neutralization to hair, as the material added is expected to saponify before it reaches the hair, and effectively becomes soap. For example, the combination of guanidine carbonate with fatty acids to produce guanidine soaps has also been the subject of studies in relation to their detersive effects, see Poliakoff et al., “Guanidine Soaps”; Industrial and Engineering Chemistry 335-337 (February 1948).
As yet another disadvantage of the known formulations, acidic shampoos generally contain water soluble acids (not fatty acids), and as such, present the expected problems of further stripping and damaging the hair. In fact, this is true of all shampoos, not just acidic neutralizing shampoos.
Relaxing human hair is a destructive and irritating process that is known to strip the hair of some or even all of its natural fatty acids, often leading to hair that is dry, brittle and dull. Neutralizing shampoos that are typically used after the relaxer can further strip away the fatty acids and other lipids due to their detergency effect. Thus, there is an ongoing need to develop compositions that relax human hair but avoid damage to the hair. The hair neutralizing compositions, systems, kits and methods of the present invention avoid at least some damage caused by the typical relaxing process.